Modeling and analysis of friction stir welding processes

Fundamental, science based modeling and understanding of the friction stir welding process can greatly reduce the cost and cycle time of its application in joining operations. Modeling and simulation were used in a comprehensive thermomechanical framework that includes all relevant mechanics and thermodynamics. The three-dimensional analysis captures the coupling between tool geometry, heat generation, and plastic flow of the material under complex asymmetric thermomechanical loading conditions present in friction stir welding processes. Model validation results with detailed marking and thermocouple experiments are outlined. Model predictions are crucial to be able to follow the complex evolution of material deformation and microstructure. The deformation and flow patterns are important in avoiding voids and weld defects in FSW design. Tracking changes in microstructure is necessary for optimization of specific properties such as mechanical and fatigue strength and determines the extent to which this process can be applied in aerospace joining and assembly operations.